1. Field of the Invention
The present invention relates to an internal power voltage generator of a semiconductor device, and in particular to an improved internal power voltage generator of a semiconductor device which can actively control standby tape pumps and active tape pumps according to a magnitude of an internal power voltage.
2. Description of the Background Art
In general, an internal power voltage generator is a circuit for generating an internal power voltage used in a semiconductor device. A conventional internal power voltage generator includes standby tape pumps operated when power is supplied, and active tape pumps operated when the internal power voltage is used in a large volume. The operation and disadvantages of the conventional internal power voltage generator will now be described with reference to the accompanying drawings.
FIG. 1 is a block diagram illustrating the conventional internal power voltage generator including a base voltage generating unit 12 having i standby tape pump units 12_i and j active tape pump units 13_j, and a high voltage generating unit 14 having k standby tape pump units 14_k and n active tape pump units 15_n.
The standby tape pump units 12_i of the base voltage generating unit 12 are operated when an external power voltage Vext is received, and the active tape pump units 13_j thereof are operated when an internal power voltage Vint is used in a large volume.
In the same manner, the standby tape pump units 14_k of the high voltage generating unit 14 are operated when an external power voltage Vcc_ext is received, and the active tape pump units 15_n thereof are operated when an internal power voltage Vcc-int is used in a large volume.
For example, the standby tape pumps are operated in a power down mode using a small amount of internal power voltage, and the standby tape pumps and the active tape pumps are all operated in a normal operation. In the case of the DRAM, the active tape pumps are operated in a row operation.
However, the conventional internal power voltage generator has a disadvantage in than a number of the standby tape pumps and a number of the active tape pumps are decided by simulation before fabrication of the semiconductor device. Accordingly, when a defect is generated after finishing the fabrication of the semiconductor device, it is impossible to adjust the numbers of the standby tape pumps and the active tape pumps.
That is, since the numbers of the standby tape pumps and the active tape pumps are fixed before fabricating the semiconductor device, if the internal power voltage proves to be different from a presumed value or variations are made due to an external environment after the fabrication of the semiconductor device, the numbers of the standby tape pumps and the active tape pumps cannot be controlled.
Therefore, it is an object of the present invention to provide an internal power voltage generator of a semiconductor device which can actively control standby tape pumps and active tape pumps according to a magnitude of an internal power voltage.
In order to achieve the above-described object of the present invention, there is provided an internal power voltage generator of a semiconductor device including: an internal power voltage generating unit composed of a base voltage generating unit having a plurality of base voltage pumps, and generating an internal base voltage from an external power voltage according to a first control signal, and a high voltage generating unit having a plurality of high voltage pumps, and generating an internal high voltage from the external power voltage according to a second control signal; and a control unit for generating the first control signal for controlling a number of the pumps of the base voltage generating unit and the second control signal for controlling a number of the pumps of the high voltage generating unit according to a magnitude of an internal power voltage consumed in the operation of the semiconductor device.
The control unit includes: a detecting unit for generating a signal detecting the magnitude of the internal power voltage in the operation of the semiconductor device; a register unit for storing a data value for adjusting the number of the pumps according to the output signal from the detecting unit; and a pump control unit for receiving the output signal from the register unit, and generating the first and second control signals.
In addition, the control unit further includes a data increasing/decreasing unit for increasing or decreasing a value to be stored in the register unit according to the output signal from the detecting unit.